Manufacture of artificial stone.



, tity sufficient to absorb from said mass the UNITEDSTATESPATENT oEFroE.

JOHN C. HENDERSON, or oAKLANn, oALIroRNiA.

MANUFACTURE or AarIFIcIAI. STONE.

Specification of Letters Patent.

' Patented April 28, 1908.

Application filed November 16, 1907. Serial No. 402,48i.

Portland cement as a binder is conducted in one of'three ways; first, by tamping a mass into anon-porous mold; second, by compressing a mass by means of machinery; and, third, by pouring a semi-liquid mass into an absorbent mold. The first of these methods produces a stone which is generally dead in color,- has friable arris, and is extremely porous. The second method has the defect of limiting the size of stones which it is practicable to make. The third method produces a stone which is slow to get its strength and which has friable arris. Moreover, by none of these methods is it practical to produce a stone which can be veined in imitation of marble.

As distinguished from the ordinary methods, my invention consists essentially in pouring into. a substantially non-porous mold a fluid aqueous mass of Portland cement, either neat or mixed witha fine aggregate such as powdered marble dust, and then, before the initial set of said mass, applying to. its top surface dry Portland cement in quanexcess of water.

Tamping and other mechanically roduced compression are thus avoided, w ile the necessary absor tion of the water excess, instead of taking PELCB downwardly, as in a orous mold, takes place upwardl thereby eaving the bottom of the mol content, which subsequently upon removal becomes the face of the stone, hard and smooth. The ulpward absorption tothe back of the stone, :1 so results in producing a stone from the face of which the excess of alkali has been removed, thus removing the cause of checking and cracking which are always found 111 Work made from neat or too rich cement.

My invention consists also, in connection with this essential feature, of other and additional steps, which I shall hereinafter fully" describe, and which result, as a whole, in a stone which is dense and practically impervious to moisture, is notrestricted in slze, is one which can be veined toimitate marble, is capable of being highly. polished, can be made strongly in thin masses, and has extremelystrong arris. 1

' These are the objects of my invention, and their attainment'will now be readily understood from a full description of my rocess.

In carrying out my rocess, t e mold,

which may be of any sultable form and of proper non-porous or substantially nonporous materials, such as glass, wood or plaster properl treated to render it non-porous, or-met'al, is first lubricated with any substance or mixture having the necessary sli pery properties, and yet not'injurious to t e material to be molded.' Such a lubricant I have found in a mixture of turpentine and a vegetable oil, say, linseed oil, in about equal arts; though this proportion is not absoute, and it may be varied; with, however, a

preference for a slight excess of turpentine,. which while tending to further diminish any injurious effect which the oil might have on the material, is yet not suflicient to materially reduce the lubricating quality of the mixture. The purpose and effect of this lubrication of the mold are two-fold: first, to enable the mass to be easily removed from the mold, and, second, to provide such a pro er surface that the cast of cement will sett e and so adjust itself that u on removal, it will be found to be free from b ow holes and perfectly smooth. I then take Portland cement, either neat or with the addition of col oring matter, or mixed with a fine aggregate such .as powdered marble dust, as may be desired, and mix it with Water to an extremely stone having'a thickness of about one-eighth of an inch, though this may be varied as desired according to the size of the stone to be made and the purpose for which it is to be 'used. Before the initial set of this fluid mass takes place, I sprinkle its top surface with dry Portland cement in an amount sufficient to absorb the excess of-water con tained in the mass, as may be readily determined by the practical worker. The mass is then allowed to remain in the mold until the final set of the cement, when it may be removed and properly seasoned in the manner known to manufacturers of artificial stone. This is the simplest sequence of my process,

I and while it embodies the essential and neces- ,This enters and sary step or feature involved in all its variations and additions, to wit, the absorption from above, by the application of the dry Portland cement, of the excess of water from the extremely fluid aqueous mass ofPortland cement first poured into the mold, my process contemplates other and further steps, according to the results desired to be obtained. These I shall now describe.

The stone roduced'as abovedescribed, is, as stated, on y a thin one. If it be desired to produce a product, such as a floor-tile, the process of pouring the fluid aqueous mass of Portland cement into the mold, and sprin klingits top surface with dry Portland cement is repeated directly upon the first mold content; that is to say, after what may be termed the first mold. increment, comprising the fluid mass and the dry cement, is complete, a second fluid aqueous mass of Port and cement is poured upon the first mold content, and the top of said second mass is sprinkled with dry Portland cement, to form a second mold increment like the first, and so on until the aggregate stone is carried to a proper thickness. In this repetition, I find that the several increments, by interabsorption, so consolidate that they cannot be distinguished in the product, but present a single homogeneous stone.

If it be desired to produce a slab of stone, the first completed mass is backed with a proper mixture of concrete, and when set, the slab thus formed is removed from the mold.

. If it be desired to vein the face of the stone in any manner to produce ornamental effects, or an imitation of marble, for example, I proceed as follows :I first make a veining material from Portland cement and color and water, making said material of a little thicker consistency than that of the fl'uid mass heretofore described. This veining material I then spread in a thin layer in the previously lubricated mold, forming in it veins or cloud effects seen in natural marble. Then I gently pour the fluid aqueous mass of Portland cement, either neat or mixed, as stated, with marble dust, into the mold, Without disturbing the tracings or veins of the material used 'for the veining effects, and I then apply the sprinkling of dry Portland cement, as before. The stone when removed from the mold will present on its face the veinings and cloud effects of the natural marble.

' After the stone, formed by my process, is

prpperly cured, say in about thirty dafys, its su ace is treated with a coating of oil, or example, linseed or olive oil, or other slow drying vegetable oil, 1preferably ap lied warm.- fil s the pores o the cement Portland cement into a non-porous mold,

and then, before the initial set of the mass, applying to its top surface dry Portland cement in quantity sufficient to absorb from.

the mass the excess of Water.

2. In the manufacture of artificial stone, the improvement in the method, which consists in first lubricating a non-porous mold; then pouring into said mold a fluid aqueous mass of Portland cement; and then, before the initial set of the mass, applying to its to surface dry Portland cement in quantity su ficient to absorb from the mass the excess of water. V

3. In the manufacture of artificial stone, the improvement in the method, which consists in first pouring a fluid aqueous mass of Portland cement into a non-porous mold; then, before the initial set of the mass, applying to its top surface dry Portland cement in quantity sufficient to absorb from the mass the excess of water; then pouring u on the mold content a second increment o a fluid aqueous mass of'Portland cement; then ap plying to the top surface of the second increment, before its initial set, dry Portland cement in like quantity to the first; and so on to complete the desired thickness of the stone.

4. In the manufacture of artificial stone, the improvement in the method, which con sists in first veining in a non-porous mold a fluid aqueous thin coating of colored Portland cement; then pouring upon said veined coating a fluid aqueous mass of Portland cement; and then, before the initial set of the mass, applying to its top surface dry Portland cement in quantity sufficient to absorb from the mass the excess of water.

5, In the manufacture of artificial stone, the improvement in the method, which consists in first applying to a non-porous-mold a lubricant; then veining upon said lubricant a fluid aqueous thin coating of colored Portland cement; then pouring upon said veined coating a fluid aqueous mass of Portland cement; and then, before the initial set of the mass, applying to its top surface dry Portland cement in quantity sufficient to absorb from the mass the excess of water.

6. In the manufacture of artificial stone,

the improvement in the method, which conthen, before the initial set of the mass, applying to its top surface dry Portland cement in quantity sufficient to absorb from the mass the excess of water; and then applying to the mold. content a backing of concrete.

7. In the manufacture of artificial stone,

v sorb from the mass the excess of water, and,

finally, when the completed stone is removed from the mold, coating its face which was in contact with the mold, with oil as a filler.

8. In the manufacture of artificial stone, the improvement in the method, which consists in pouring a fluid aqueous mass of Portland cement into a non-porous mold, and, before the initial set of the mass, applying to its top surface dry Portland cement to absorb from the mass the excess of water; then, when the completed stone'is removed and cured, coating its face, which was in contact with the mold, with oil as a filler, and, finally, treating said face with turpentine and wax and polishing the same.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses. 7

JOHN C. HENDERSON.

Witnesses:

WM. F. BooTH, D. B. RICHARDS. 

